## CryptoDB

### Paper: Public-Key Watermarking Schemes for Pseudorandom Functions

Authors: Rupeng Yang , Department of Computer Science, The University of Hong Kong; Institute of Cybersecurity and Cryptology, School of Computing and Information Technology, University of Wollongong. Zuoxia Yu , Department of Computer Science, The University of Hong Kong; Institute of Cybersecurity and Cryptology, School of Computing and Information Technology, University of Wollongong. Man Ho Au , Department of Computer Science, The University of Hong Kong. Willy Susilo , Institute of Cybersecurity and Cryptology, School of Computing and Information Technology, University of Wollongong. Search ePrint Search Google Slides CRYPTO 2022 A software watermarking scheme can embed a message into a program while preserving its functionality. The embedded message can be extracted later by an extraction algorithm, and no one could remove it without significantly changing the functionality of the program. A watermarking scheme is public key if neither the marking procedure nor the extraction procedure needs a watermarking secret key. Prior constructions of watermarking schemes mainly focus on watermarking pseudorandom functions (PRFs), and the major open problem in this direction is to construct a public-key watermarkable PRF. In this work, we solve the open problem via constructing public-key watermarkable PRFs with different trade-oﬀs from various assumptions, ranging from standard lattice assumptions to the existence of indistinguishability obfuscation. To achieve the results, we first construct watermarking schemes in a weaker model, where the extraction algorithm is provided with a “hint” about the watermarked PRF key. Then we upgrade the constructions to standard watermarking schemes using a robust unobfuscatable PRF. We also provide the first construction of robust unobfuscatable PRF in this work, which is of independent interest.
##### BibTeX
@inproceedings{crypto-2022-32099,
title={Public-Key Watermarking Schemes for Pseudorandom Functions},
publisher={Springer-Verlag},
author={Rupeng Yang and Zuoxia Yu and Man Ho Au and Willy Susilo},
year=2022
}